Out of print publication, available as a photocopy only

A coastal revetment is a cladding to the sloping surface of either the natural shoreline or a flood embankment, which protects and stabilises it against erosion by wave action. Adequate maintenance of coastal revetments, of which there are about 700 km around the British coastline, can entail both practical and economic problems, due to costly or labour—intensive maintenance methods and to the inaccessibility of some sites.

This publication is based on a questionnaire survey of authorities throughout Britain responsible for maintaining coastal revetments, supplemented by follow—up discussions and a short desk study. Its purpose is to investigate and report on existing maintenance requirements and methods; new or improved methods which might reduce cost and/or improve efficiency; and the economics of maintenance in the context of the overall effectiveness of coastal defences. Short guidelines are then formulated both for the maintenance of existing revetments and for the design of new ones, and a number of areas are highlighted where further research would be valuable.

The questionnaire survey was carried out in conjunction with Southern Water. Subsequent stages were carried out for CIRIA by L Summers, a coastal engineering consultant formerly with Sir William Halcrow & Partners, assisted by other specialists on the project steering group.

The publication is divided into two main sections. Part A describes and illustrates the types of revetment reported, which are principally of rock or concrete construction, and summarises their location, length and function. The overall factors governing performance, and the actual reported performance of specific revetment types, are then discussed. Regional problems due to loss of foreshore are identified, and an outline is given of the maintenance policies and methods of the various authorities responsible for revetments. This is followed by a summary of the maintenance costs for different revetment types. The approach to maintenance planning is set out with a view to achieving the minimum overall outlay on maintenance and replacement.

Part B sets out guidelines for the design and maintenance of revetments. These provide an overall framework for assessing the effectiveness of existing revetments and planning their maintenance or reconstruction. Emphasis is laid on the importance of considering the performance of a revetment throughout its serviceable life, and of acquiring adequate data on site conditions. Overall design parameters, including water levels, wave conditions, joint probability of events, foreshore and shoreline and environmental aspects, are described, as are specific design elements, 8uch as height of the revetment, profile of face of the revetment, profile of rear face of the flood embankment, allowance for settlement, toe protection, and overall stability of the revetment under wave action. This is followed by a discussion of construction considerations, such as access and selection of materials, and a summary of the methods of benefit cost analysis by which a proposed coastal defence scheme can be appraised. A bibliography is included.